Self-locking nut



1 April 11, 1944. w. RUTHVEN- 2,346,456.

SELF-LOCKING NUT` r Filed Jan. 14, 1943 2 Sheets-Sheet 1 April 11, 1944. w,'RU1-`HVEN 2,346,456 SELF-LOCKING- NUT l l Filed Jan. 14, 1943 2 Sheets-sheet 2 fun@ l fw

A/"I l'2/ 'l1 A' l l 'Il .ll- 2 f lgaf 26 I T 28 v INVENTOR 30 3 ATTORNEYS UNITED" srA'rr.

Patented -pn' ll, 1944 SELF-LOCKING NUT wimani animen, oakrark.' nl., signor u ailied Control Company, Inc.; New York. N. Y.,-

` a corporation of New York Application January 14, 1943, Serial No. 472,333

20 Claims.

This invention relates to self-locking nuts of the type including a resilient insert and to the manufacture of such nuts. v t

An object of this invention is an improved selflocking nut of the ,type in which a nut member is `provided with a recess to receive a resilient locking member and prevent rotation of the locking membe relative to the nut member.

An o ject of this invention is a self-locking nut formed from a metal blank and of integral construction except for the resilient insert.

A further object of this invention is a method of producing such a nut from a metal blank. In the manufacture of the self-locking nut embodying this invention from a metal blank,

pressure is applied to the metal blank to convert said blank by flow of the metal thereof into a polygonal shell having a bottom at least as thick as the original thickness of the blank and a wall of considerably less thickness than the original thickness of the blank. The socket of the shell is of polygonal configuration and into it is intro-` duced a locking member whichmay be a per-v forated resilient insert `of similar conguration, after which at least a portion of the edgeoi the said member in the shell. The shell bottom is t provided with a threaded bore to receive a bolt which extends therethrough into the aperture of the resilient insert with the threads of the boit cooperating with the locking member to retain the bolt against accidental romoval from the nut.

The blank vmay be of different .shapes as the v section drawing die of the same cross-section as the, desired exterior shape of the nished nut by means ofa polygonal punch of the same crosssection as the desired interior shape of the nut f spcket. As the blank is `forced into the die the central portion thereof or the part which is to become'the nut bottom may be slightlythickened and the remainder isironed to less thickness than the thickness of the original blank and converted into socket wail portions parallel tothe die axis and of suilicient height to equal the thickness of the resilient insert later to be introduced into the socket. The metal'of'the scallops produces intemi tapering tabs proiecting'from the rim of the socket wall,whi`ch tabs are formed simultaneousl'y with thetormation of the shell. After thev introduction of the Vinsert into *the shell, the 60 2li shell wall is inturned over the insert to secure (ci. iow tabs are turned in over the insert to hold it in the socket. The base of each tab is co-extensive with the top edge of its corresponding wall portion and the taper of each tab is suiilcient that when 5 the 4tabs are turned in over the insert there is no interference between adjacent tabs. This arrangement provides a continuous clamping flange 'for the insert. along the rim of the socket thereby securely retaining the insert in the socket and overcoming a defect in previous self-locking nuts in winch the insert was insecurely held to suchextent that the insertion of a bolt into the nut caused the insertto pop out of the shell. According to this invention, the shell, together with its wall portions equipped vwith tapering "tabsis produced in a one-operation procedure, thereby reducing production and tool cost to the minimum. l

Although so far, best results have been obtained from a 4substantially circular scalloped blank, blanks of other configuration may be used. However, in each instance, the metal of the blank f generally corresponding to the metal of the scallops of the circular scallopedv blank produces tapering tabs extending from the top edge of each wall portion. The shapeoi the tabs thus .produced depends upon the con-nguration of the original blank as well as the design of the tools, by means of which the original blank is converted into a shell.

Fig. 2 is a section on theline 2-'2 of Fig. 1;"

Fig. 3 isa plan view of one formv of blank for tion:

Figs. 4,' 5, 6 and Ilkillustrate successive opera- Other objects, novel features and advantages or use in producing a nut aA ording to the inventions in one procedureo! converting the blank l into a shell according to this invention;

Fig. 8 is an elevation partly in section of the shell produced bythe steps illustrated in Figs. 4 to 7; y

Fig. 9 is a substantially on the line I-l of Fig. l; 4

Fig.A 10 is a section substantially on the line lli-ll of Fig.ll;

Fig. 11 is a vertical section of an apparatus for eiecting the conversion steps illustrated in Figs. 4 to 7; v l 4 Figs. 12 and 13 are views Asimilar to Fig. 10 of modifications and V Fig. 14 is a fragmentary view similar to Fig. 11 of a modiiication. v

As illustrated in Figs. 1, 2, 8 and 9. bodying this im ention comprises a polygonal a mit emsection `of the completed nut taken metallic body or bottom I having acentral .threaded aperture 2 and a hexagonal socket composed of connected 'flat wall portions 3 integral with said bottom. A resilient insert 4 of complemental conguration to the socket is received therein and has an opening 5 therethrough alined with the axis of the thread of the aperture 2 and of a diameter less than the majordiameter of the aperture thread. Each wall portion 3 has an integral arcuate extension of tab 6, the base of which is co-extensive with the top edge of the wall portion. The tabs B are bent inwardly. over the position shown in Fig'? in which the presl sure pad is rigidly supported by means later to be described. During the downward-travel of the insert to hold it in the socket and the taper of each tab is such that when folded'in it does not interfere with the adjacent tab. Together the tabs .provide a continuous clamping flange along the rim of the socket to retainthe insert 4 securely inplace and prevent ejection of the insert from the socket upon insertion of a bolt into the insert through the threaded aperture 2. In this nut, the end surface 'Iy constitutes the face of the nut. As shown in Fig. 2, a bolt 3 passes through two or more plates 9`or the like to be held together and is first entered into the bottom aperture 2, after which it passes throughthe bore 5 ofthe insert i in the surface of which it embosses its thread. The surfacel 'I thus constitutes the abutting face of the nut when the nut is drawn home. The resilient insert 4 is shown herein as being non-metallic but may be metallic. A blank I from which the nut above described may be made is shown in Fig. 3 and is of generally circular configuration formed with scallops II. Also, the blank is preferably provided with `a central perforation I2. Blanks of other congura- 'tion. for example, a true circle may also be used but experience to date has proven the blank 'of Fig. 3 to be most satisfactory.

Figures 4 to 7 inclusive illustrate the preferred procedure of constructing a shell from a blank..

In these iigures, I3 designates a fixed die block formed with a flared mouth die of hexagonal con- .figuration and of the same size as the exterior of the nut which is to be constructed and having' its major diameter at least equal to the minor diameter of the blank i0. A pressure pad "I4 is mounted in the die for movement axially there, of and is provided with supporting and operatingnmeans which will be later described. A spear I projects upwardly from the central portion of a the pressure pad and is materially less in crosssection than the pad.4 A holder IE having a central aperture or nest of the same size and shape as the blank I0 'is provided for locating the blank on the block I3 coaxial of the die with the scallops II properly oriented with respect to the die. A hexagonal punch Il is supported fon reciprocathe punch I1, the blank I0 is subjected to a drawing operation as illustrated in Figs. 5 and 6. During the drawing operation, some of the metal of the blank is caused to iiow centrally thereof slightly increasing the thickness of that portion of the blank which later becomes the bottomone of the shell. Also, in the case of some of the softer steels, the bottomv of the blank tends to bow downwardly. In addition, the inward flow of metal contracts the perforation I2 thereby minimizing to some extent the tendency of the central portion of the blank to become thicker. The remainder of the blank is ironed to less thickness than the original blank to form the wall portions 3 with the metal in the scallops `II being projected beyond the top edges of the wall portions 3 to form arcuate tabs 5. Upon arrival of the pressure pad I4 at the position shown in Fig.' 7, the punch I'I exerts sumcient pressure to straighten out any bow that may have been Vformed on the under surface of the bottom portion I during the drawing operation. y'Although during the forming operation the perforation I2 decreases in size, the spear I5 remains fully projectedi'nto the underface of the blank or else is fully projected thereinto by the pressure applied to the blank by the punch after the pressure pad I6 has reached the lower limit of its travel.

In the progress of the blank' through the ared open-end of the tube into the interior of the tube, the blank is progressively drawn from its original contour into a polygonal exterior contour and there is simultaneously formed a polygonal wall extendingatright angles to the plane originallyoccupied by `the blank. This action is accomplished by utilizing for the drawing operation a plunger of polygonal contour corresponding to the shapeljof the tube and whose maximum cross-sectional areais less than the minimum cross-sectional area of the tube. The

polygonal Wall thus formed is continuous and consists of a connected series of flat wall portions extending at right angles to the original positon of the blank and defining a polygonal space while each wall portion is formed with an arcuate extension at its outer edge. The bottom scribed is illustrated in Fig. 8. Theperforation I2 in the'bottom is of considerably less diameter than that required for the threaded aperture of tion into and out of the die and means, later to be described, are provided for effecting recipr cation of the punch. The punch is smaller in size than the die and may be slightly tapered, the size of the punchcorresponding to the interior size of the shell of 'the finished nut. O n the lower end of the punch is provided a circular rib I8 of at least as great diameter as the maximum diameter of the *spear I5.

After the blank I@ has been positioned as shown in Fig. 4 with the pressure pad It in raised position and the spear Iii projecting into the perforation I2, the punch II is moved downthe completed nut and terminates in a countersink Ia of slightly larger maximum diameter than the threaded aperture in the completed nut. The bottom I is next punched and tapped to provide the threaded aperture 2 which constitutes a continuation of the countersink 1a. The assembly of the nut is completed by introducing the insert 4 into the socket and turning the tabs 6 inwardly over the insert to secure it in the socket.

In Figs. 10 and 1l, apparatus is illustrated for effecting the conversion procedure above described. The die block I3 is attached by bolts wardly into contact with the top surface of the v l blank and sufiicient pressure is applied by the punch-reciprocating means to cause downward movement of theblank I 6 and pressure pad IE through the positions shown in Figs. 5 and 6to f and pass through -surface of the and punch. Also,

i bottom of the into the die, the `spear 4dictate s. The circular clamping the blank 23 of the press androds l24 extend downwardly from the head 23 through the die block I3 and frame 2|). A plate 25 underlies the frame 20 and has apertures l rods 24, each of which is equipped with a nut 25 bearing against the underface of the ,plate 25. Apair of rods 21 are slidably mounted in the frame with their upper ends engaging the bottom face of the head 22 and their lower ends engaging the upper face of the plate 25.. A pair` of rods 28 are carried by the frame 20 apertures in the plate 25 las well as through apertures in a cross bar 29, each rod 28 being equipped with a head 30 which supports the bar 29. Ay spring 3| .surrounds each rod 28 vvand is interposed between the plate 25 and bar 29. In the position shown in Fig. 1l, the springs 3| are under merely enough tension to hold the pressure pad 22 'in its upper position. The nest I6 is attached tothe die blocky by bolts 32 and is oriented with respect to the dieas shown in Fig. 10 so as to line up-the scallops I2 with the iiat faces of .the die.

through which extend-the converted by a single 4-pun'ch and die as 4different configuration. Also, with certain types In the operation of `this device, the punch |1 moves downwardly thereby contacting the rib I8 with the top surface ofthe blank I0, the bottom surface of which is engaged by the pressure pad Il and the springs 3| arecompressed to oppose downward movement of the pad. Continued downward movement of the punch I1 forces the blank I0 and pressure pad I4 togethcr with the rod 21 and plate 2s downwardly against the pressure of the springs `3I. After completion of its downward stroke,` the punch .I1 returns to its uppermost position lavingthe formed shell at the bottom of the die. The shell is retained at the bottom of factthat there is a greater area. of contact between the outer surface of the shell and the die than between the inner surface of the shell and the surface of the punch and consequently the friction between the die and shell exceeds the pressure between thedie `and die is sufncient to retain the shell at the die despite the upward pressure exerted on the head 22 by the springs 30. However, as the punch nears the upper end of its stroke, the nuts 25 engage the plate 25 to lift it upwardly, thereby lifting up the pressure pad 22 and eiecting the socket from the die.

During movement of the punch and blank I5 acts as apilot to prevent any lateral movement of the blank thereby insuring even drawing of the, blank and uniformity in the wall portions 3 as well as in rib I8 also assists in I0 against lateral movement during the drawing operation. The spear and rib thus cooperate to assure uniform drawing although as a practical matter the spear |.'i`

is completely efficient as'a pilot. The springs 3| oppose downward movement of the pad I4 and supplies clamping pressure between the pad and the punch.

With someI of the harder steels, the bowing action previously referred to may be absent so A that the pressure pad does not have thefunction of providing a nat' compact face. However, with such metal as well as with the softer metal, the pressure pad in I5 provides a countersink in the contact face thereby eliminating a countersinking operation after the removal of the shell from the press.

Bythe procedure just described, the blank is the die due to the the friction between the shell combination with the spear used except that the nest configuration. Also, the tabs '-.event the shell will be agonal one. In

.over the tabs to wform a complete nut.

'A nut may be made according to this invention from a true circle blank. In construction such a 10.

nut, the same procedure and apparatus will be I5 will be of circular 6 will be of slightly diierent configuration due to the difference in available metal. However, may also be varied by suitably designing the well as by utilizing -blanks of of metal, the blank may be imperforate, in which after its completion.

A further form of blank which maybe used to produce the nut of this invention is a hexthe construction of the shell from a hexagonal blank, the blank is oriented with respect to the die so that each corner of the :blank lies midway between two corners of the die. The corner portions of the blank are converted into the tabs 6 of the shell. The procedure of converting theblank into the shell is the same as previously described and use is made of the same apparatus except that the' nest is of hexagonal configuration and is properly oriented to line up the Iblank in proper relation to the die.

Other forms of blanks which are symmetrical with respect to a point and so cular but with regular indentations in, the periphery may be used to produce the nut of this invention by the procedure herein described.

Fig. 12 illustrates a circular blank Ilia arranged i the nest I5 above the hexagonal die in position to be converted into a shell by being forced into the die bythe punch I1. Fig. 13 illustrates a hexagonal blank |0b arranged in the nest I5 above the hexagonal die with the blank so arranged that its 4corners lie midway between the corners of the die. forced into the die to convert the blank into a shell; The material in the blank extending beyond the faces of the die produces the tabs l.

While in the usual practice of the procedure herein disclosed theblank is processed cold, it is to be noted that if the preheated to render it more workable. However, the procedure of converting the blank into a shell is the same irrespective of whether the blank is processed cold or ho The tabs l are herein disclosed as being of i substantially arcuate configuration but it is to -be claims, this configuration of tab is defined as` tapered.

By properly regulating the extent of the ad#- vance of the punch lntothe die with relation to 'the original thickness of the blank, the .operation performed on the blank may combine extrusion of the metal of the blank as well as drawing of such metal to produce the shell as above described. In such operation, metal is caused to flow by the application of pressure to the blank from the'bo'dyportion up into the wall portions.

thereof provided with intethe shape of the tabs V pierced for the lrsttime aregenerally cir- The blank IIib is ready to be blank is composed of metal' of greater Athan usual hardness, the blank may be the top edge A thread therein and end of the nut and hvihs a continuous plane surface bottoni fn The one-operation procedure may, therefore. be

a combination of drawing and extrusion.

or some types of fines the metal owing into the tabs and deilnitef ly avoids the possibility of any feather-edge at the top oi' the tabs'\which might have to be re-- moved by a trimming or clipping operation.

It is of course understood that vvarious modiilcations may be made in the procedure and apparatus above described without in any way departing from the spirit of the invention as defined in the appended claims.

I claim:

1. A self-locking nut comprising a solid polygonal base having a central threaded aperture,`integral wall portions of less thickness than the base projecting therefrom in a direction parallel `to the aperture axis and dening a polygonal socket having a continuous plane surface bottom except for said aperture and a continuous wall,

veach wall portion terminating in a tapering inbase of which is co-extensive with v tegral tab the of the corresponding wall portion. and a perforated locking member in said socket of complementary shape and size to said socket to prevent relative rotation of said socket and member, each tab being inturned overy said member without interference with an adjacent tab and providing a substantially continuous clamping flange for said member along the rim` of said socket to retain 'the member in the socket.

2. A lock nut body having a concentric threaded hole and coextensive integral side walls of like shape terminating in a seriesv with the adjacent tom except for said hole, and a locking member complemental-to the shape of said socket fitted into saidsocket, the'scalloped lugs of said side walls being formed said member for permanent assembly'.

3. A lock-nut of the kind in'which an elastic, locking member is utilized to eifect'the locking action, which lock-nut comprises in combination ins from l comprising a ,solid polygonal f of scalloped lugs' and deilning.V edge of said body'a polygonal socket having a continuous. plane surface botin against the outer face of a solid metallic body having the load-carrying one end surface thereof formnut, a socket at the opposite body of polygonal configuration' ing the face of the vexcept'for 'said'thread, 4and an elastic locking member of a polygonal coniiguration complement'.l tary to the socket within the socket and having an opening therethrough alined with the axis of the thread ,of the nut body and of adiameter less than the maior diameter of the thread of the nut body, the end. in!

portion of the socket extendtially continuous flange for retaining the locking'v member against axial movement with -respect to the'nut body upon the insertion of a bolt through the nut body into the locking member.

4, sleek-nut of the kind in which e resilient insert is utilized to effect the locking action,

` which lock-nut comprises injcombination a solid inwardly over ,and engaging the surface of v lthe locking memberl and constituting a substan- `bending said tabs into he nut body of polygonal conguration and baving a continuous plane surface bottom except for said thread, the wall of which terminates in a series of tapering end portions, and a resilient in sert of a polygonal conilguration complementaryy 'to the socket within the socket and having an tially continuous i'iange for retainingfthe insert against axial -movement with respect to the nut body upon the insertion of a bolt through the nut body and into the inse 5. The method of forming a lock-nut from a metal blank which comprises locating thev blank over the -end of a polygonal die of less maximum cross-section than said' the blank B D0lygonal punch of lesscross-section than said die to force said blank into the die without material change in shape of the blank within the area corresponding to the end of said punch and convert the blank into a polygonal shell having a bottom'of approximately the same cross-section as the corresponding portion of the blank and a continuous wall of less thickness than .the original thickness of the blank comprising a connected series of flat wall portions extending iat right angles to the plane of the bottom with each wal1\ts rtion having a tapered tab extendinto said space a locking member whose shape is complementary to that defined by said wall and contact with said locking member to secure it in said space.

6. 'I'he method according to claim 5 characterised by the ration formed with scallops.

"1'. The method according to claim 5 characterized by said blank being of circular configuration. 1 Y

8. The method according to claim 5 characterized by the fact'that as the blank is forced into the die its external size is progressively decreased during at least a part of said forcing.

1 9. 'I'he method of-forming a lock-nut from a metal blank -which comprises locating the blank over the' end of a polygonalv die of less maximum Y cross-sectionthan that of blank, pressing tions extending ereignet the blank Y a polygonal' punch of less cross-section than said,die to lforce the'blank to the die into contact with a fixed abutment without material change inshape of the lank within the area corresponding to the end said punch, thereby converting the blank into apo- 1 iygonal shell' having a bottom of approximately the same cross-section as the corresponding por'- tion of the blank and 'a' continuous wall of less thickness than the original thickness of the blank comprising a' connected series of flat Wall porat right angles to the plane of the bottom with each wail portion having a tapered tab extending from its top edge and surrounding e and dening al polygonal space, providing 'a central threaded aperture in said bottom,.introducing into saidspace a locking member whose shape is complementary-to that defined by said wall and bending said tabs into contact-with said locking' member to secure it in said space.

10. 'I'he method according to claim 9 characblank, pressing against top edge and surrounding and delining.' a polygonal space, providing a central threaded aperture in said bottom, introducing blank being of generally circular terized by the blank being o! generally circular configuration formed 4with scallops. 11. The method according to claim 9 characterized by said blank being-of circular coniiguration.

12. The process of forming a lock-nut which comprises positioning a at metal blank of suitable configurationover the iiared end of a polygonal die whose minimum internal cross-section is less than that of the blank, progressively drawing said blank to a polygonal exterior contour by forcing it at least to the point of mini.'

mum cross-section of said-die without material change in shape of the blank within the area corresponding to the end of said punch and simultaneously forming a polygonal wall extendwall surrounding and denning a polygonal 4space,

prior to the application offorce on said blank Vinserting into the blank recess a member movable with said punch to pilot the blank during its ing said tabs into contact with'said vinsert tol secure it in said space.

15. The method of forming a lock-nut from a metal blank'which comprises locating the blank ing at right angles to the plane originally occupied by the blank with each wall portion having a tapered extension at its outer edge by utilizing `for the drawing operation a punch oi' polygonal contour corresponding to the polygonal shape of the die and whose maximum crosssection is less than the minimum cross-section of the die, providing a threaded aperture in the formed blank, inserting a perforatedelastic insert of a shape complementary to that'f said polygonal wall within the space defined thereby and bending said tabs into engagement with said insert.

13. The method of forming a lock-nut from a recessed metal blank which comprlses locating the blank over the end of a polygonal die of less maximum cross-section than said blank,

4Dressing against the blank a polygonal punchof less cross-section than said die without material vchange in shape of the blank within-.the area wall of less thickness than the original thickness having a tapered tab extending from its topv edge and said wall surrounding and deiining a polygonal space, prior .to the application o! force on said blank inserting into the blank recess a member movable with said punch to pilot the blank during its movement into the die, converting the blank recess into a central threaded aperture in the shell bottom, introducing into said space a perforated elastic insert whose shape is complementary to that denned by said wall and bending saidl tabs into contact #with said insert to secure it in said space.

14. 'Ihe method of forming a lock-nut from a recessed metal blank which comprises locating the blank over the end of a polygonal die of less maximum cross-section than thatof the blank. pressing against the blank a polygonal punch of less cross-section than said die to force the blank into the die into contact with a fixed abutment without material change in shape of the blank within the area corresponding to the end of said punch, thereby converting the blank into a polygonal shell having a bottom of approximately over the'endof a polygonal die of less maximum cross-section than that of the blank, pressing against the blank a polygonal punch of less crosssection than said die toforce said blank into the die without material change in shape of the blank within an area corresponding to the end of said punch and convert the blank into a polygonal shell having a bottom of approximately the same cross-section as the corresponding portion of the blank and a continuous wall of less thickness than th original thickness of the blank comprising a connected series of flat wall portions extending at right angles to the plane of the bottom with each wall portion having a tapered tab extending from its top edge and said wau sur- -rounding and denning the polygonal space, maintaining said blank against lateral movement during insertion into .said die, providing a central threaded aperture insaid bottom, introducing into'said space a perforated elastic insert whose shape is complementary to that dened by said wall and bending said tabs into contact with said 17. Themethod according to claim 15 characterized by the blank having a central recess `and said recess being converted into the central threaded aperture in the shell bottom after the formation ot the shell.

. 18. The method according to.' claim 15 characterized by' the-blank having a central perforation and said perforation being converted into section and being oriented to locate each corner midway between two corners of the die.

20. In the procedure of producing a lock-nut from a metal blank, the step which comprises locating the blank over the end of a polygonal sponding to the end of said punch and convert die of less maximum cross-section than said blank, pressing against the blank a polygonal punch of less cross-section than' said die to force saidblank into the die without material change in shape of the blank within the area correthe blank into a polygonal shell having a bottom of approximately the same cross-section as the corresponding portion of the blank and a continuous wall of less thickness than the original thickness of -the blank comprising a connected series of flat wallportions extending at right angles to the plane of the bottom with each wall portion having a tapered tab extending from its top edge and surrounding and defining a polygonal space, and providing a. central threaded aperture in said bottom. Y

' WILLIAM RUTHVEN.

. Rtent N0 CERTIFICATE oF'coRREcTIoN.

April 11 1914A;

wILLI/m RUTHVEN, f

It is hereby certified that errorl appears in the printed specification of the above numbered patent requiring correction as follows.: Page "5', second ",cogunin, line [L7-)48, claim 18, for "contrai perforation read' --centrai recesnxlinel, for perforation read recess-e; x'that the said Letters Patent should be read with'this correction therein thai: the same hay' confonn to therecord'of the case in the Pat-ent Office.

signeamd sealed' this 50th day of nay, ALD.V 19ML.

` Leslie Frzer (Seal)` Acting Commissioner of;l Patepts'. 

